Carpet tile (modular floor covering having a textile top surface or face) has historically been a product that sought to mimic the appearance of broadloom carpet and to hide or at least de-emphasize the fact that the product was modular. Achieving this result has required, at minimum, that carpet tiles or modules be placed in a flooring installation with the same orientation, and often in the same relative position on the web, that the modules had at the time they were produced. This is because conventional carpet tiles, particularly including tufted, fusion bonded, or woven face carpet tiles, normally have a “direction” as a result of (1) the manufacturing process and/or (2) the pattern on the tiles.
Conventional production of carpet tiles has also had to reflect, in designs incorporated in or placed on the face of tiles, the limitations associated with tile production. For instance, carpet tiles are typically produced by producing a broadloom floor covering “web” having a width that is a multiple of the width of tiles to be cut from it. For instance, typical web widths are approximately six feet or two meters wide. Although other techniques such as weaving are also used, the principal techniques employed for forming the textile face of such floor covering webs are tufting and fusion bonding. After attachment of backing structures to the textile face, the web is cut into tiles or modules, such as, for instance, tiles eighteen inches or one-half meter square.
The appearance of the faces of such carpet tiles are typically produced by the colors and patterns of yarns on the face of the tiles and by printing on the faces of the tiles. Printing of the face of a carpet tile can occur after the floor covering web is cut into tiles, thus making it possible to position the printing on the tile by reference to the tile edges. If the appearance of tiles is produced by tufting the face of floor covering in a particular pattern or by printing the web before it is cut into tiles, it is difficult to control with precision the position of face design elements relative to tile edges. This is true for several reasons. For instance, the face cloth portion of the floor covering web may stretch, shrink or otherwise change shape after it is produced, thereby changing the relative positions of design elements on the face cloth. This can occur, among other reasons, if the face cloth becomes disengaged from one or more tenter pins during manufacture. Expansion or shrinkage of the face cloth can also occur during heating or cooling or in the process of attaching backing structure during the manufacturing process.
It is, of course, possible to locate knives or blades used for cutting carpet tiles from a floor covering web with substantial precision relative to each other (thereby insuring that the tiles will be of a desired uniform size) and relative to other structures of the production equipment, such as tenter hooks. However, because the elements of designs on the face of the floor covering web may not be located precisely in predetermined positions relative to the production equipment (in either of the cross-web or longitudinal directions), it is difficult to cut tiles from the web with precise reference to design elements on the face of the web.
Additional considerations come into play relative to the position of the cuts across the floor covering web (i.e., transverse to its length) that will define carpet tile edges. It is impractical to use the cut that forms the trailing edge of a first set of tiles as the cut that forms the leading edge of tiles of a next set of tiles. It is instead at least frequently necessary as a practical matter to define the leading edge of every tile with a new cut by reference to which the cuts are made that simultaneously form the trailing edge of the same tile. One such new cut can, in effect, establish the reference point for multiple simultaneous cuts parallel thereto and behind the first new cut. For instance, in one known tile cutting device, two or three blade assemblies parallel to the first transverse blade assembly simultaneously cut the web, along with longitudinally oriented blades, to cut the web into eight or twelve tiles (two or three rows of four tiles across the web). The web will then have to advance at least a small distance beyond the front blade assembly before the next cuts that form the next group of tiles.
These factors, together with the other considerations described above, mean that it is at least very difficult to design and form a floor covering web and then cut it into tiles with transverse cuts that fall in precisely predetermined locations on the web.
All of these considerations, as well as others, have tended to cause carpet tile to be designed so that the location of tile-forming cuts on the floor covering web does not matter. For instance, many tiles have no pattern on the tile face and are made in a solid color with either a random yarn pattern or no yarn pattern. Other carpet tile designs use relatively small design elements, again often in a random-appearing pattern, so that tile edges that transect the design elements will not produce unacceptable appearance. Yet another approach is to produce tiles without a pattern on their faces and then print patterns on the faces after the tiles are cut to size and it is possible to position the printing by reference to tile edges.
In light of these considerations, tufted or fusion bonded face carpet tile or other textile face modular floorings generally have not been produced with centered, prominent design elements incorporated in the textile face during manufacture (rather, for instance, than printed on that face).